U.S. Pat. No. 5,135,058, entitled Crane-Mounted Drill and Method for In-Situ Treatment of Contaminated Soil, discloses an elongated hollow drive shaft mounted for rotation about its axis while being supported in vertical orientation. The upper end of the drive shaft is connected for selected injection of fluid under pressure into the shaft and a drill is affixed to the lower end of the shaft for drilling a hole downwardly through the soil. The drill comprises a hollow sleeve mounted to the lower end of the shaft and extending therefrom coaxially with the shaft. A pair of drill blades are cantilevered from the sleeve, and extend outwardly therefrom at right angles diametrically opposite to and aligned with each other.
Each blade is of identical uniform cross section and carries a plurality of radially spaced drill teeth oriented tangentially of the sleeve along a leading radial edge of the blade. A hollow pipe extends along the trailing edge of each blade and has orifices for injecting fluid from the sleeve and pipe into the earth as the blade is rotated. A plate is affixed to each blade to deflect soil away from the nozzle orifices as the drill is rotated.
In operation, when drill teeth are brought into engagement with the earth surface, continued driving of the drill combines with angle of attack of the teeth to propel the drill downwardly into the earth's surface at a rate controlled to obtain proper mixing and penetration of the soil. During rotation, a deflector functions to shield nozzle orifices from dirt flowing over the upper surface of the blades. During drilling into and/or removal from the earth, fluid under pressure is fed to the Kelly bar by a fluid control system. Fluid treatment media may comprise hot air or steam to drive off volatile organic compounds that are collected by a shroud; microbes, hydrogen peroxide or a phosphorous/nitrogen solution for bioreclamation for creosote-contaminated and hydrocarbon contaminated soil; cement, flyash or silicaceous material to solidify and entomb heavy metals; or a neutralizing agent to stabilize pond sludge.
In order to sample and test at progressive depths the condition of the loose soil after treatment, it has heretofore been normal practice to obtain samples one by one by lowering to progressive depths a tool having means to retrieve a sample which may be raised to the surface for inspection.